Bit-stock.



No. 869,639- PATENTED OCT. 29. 1907. J. O. MICHAUD.

BIT STOCK.

APPLIOATION FILED FER-23, 1907.

JOSEPH O. MIOI-IAUD, OF FORT KENT, MAINE.

BIT-STOCK.

Specification of Letters Patent.

Patented Oct. 29, 1907'.

Application filed February 2 0 Serial No. 358| 33- To all whom it may concern:

Be it known that I, .lossrn O. Mienxnn, a citizen of the United States. residing at Fort Kent, in the county of Aroostook and State or'Maine, have invented certain new and useful Improvements in Bit-Stocks, of which the following is a specification.

in tool holders of the type embodying a chuck with relatively movable jaws, the gripping action is not always such as to prevent loosening of the bits or other tools held in working position. This is due in a great measure to the taper of the socket formed between the jaws and to the means for pressing the jaws together and which means holds the jaws in fixed position.

The present invention provides a novel arrangement of parts whereby the jaws are normally pressed together by a spring action, thereby automatically taking up any slack between the jaws and the shank of the bit, drill, or other tool, so as to prevent any looseness.

For a full description of the invention and the merits thereof and also to acquire a knowledge of the details of construction and 'the means for effecting the result, reference is to be had to the following description and accompanying drawings.

While the invention may be adapted to different forms and conditions by changes in the structure and minor details without departing from the spirit or essen tial features thereof, still the preferred embodiment is shown in the accompanying drawings, in which:

Figure l is a detail view of a bit stock embodying the invention. Fig. 2 is a side view of the bit stock, parts being broken away and showing the jaws separated, and the operating lever moved to hold said jaws open. Fig. 3 is a view similar to Fig. 2 showing the jaws closed. Fig. f is a sectional view on the line a'-a of l ig. 2.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters.

The bit stock comprises a shank l which may form a. continuation of an ordinary brace or constitute a hand piece or other form of holder. The shank is provided with a fixed jaw 2 which is arranged to one side of a prolongation of the axis of the shank, the latter being offset at 3 to throw the jaw 2 to one side. A complemental jaw 4f cooperates with the jaw 2 and is movable and is retained in place by a suitable fastening 5 consisting in the present instance of a screw which is let into the fixed jaw 2 and passes through an opening near the inner end of the jaw f. The jaws 2 and f are so arranged as to hold a bit, drill or other tool about in line with the axis of the shank The inner faces of the jaws 2 and f are recessed in the usual manner to conform approximately to the shanks of boring tools, such as angers and drills.

The jaws 2 and f are normally pressed together by a spring action and for convenience, a heavy or stout flat spring 6 is placed along side the fixed jaw 2 and is fastened at one end to the shank 1 and is connected at its outer, or free end, with the movable jaw f by means of a link '7 the same being approximately of U-form and having its closed end fitted in a roll at the outer end of the spring 6 and having the extremities of its side members inwardly bent to form projections 8 which enter openings in the sides of the operating lever S) which is pivoted at 10 to the movable jaw f. The spring 6 normally tends to close the jaws so as to grip the tool or article inserted between them.

The operating lever 9 has its handle portion made hollow and adapted to inclose the shank when moved to a position so as not to exert any restraining influence upon the spring (5, whereby the latter exerts its tension to press the jaws together and grip that which may be placed between them. One end of the operating lever is bifurcated and the bifurcations 11 embrace opposite sides of the movable jaw 4 to which they are pivoted by means of a pin or like fastening 10. The ends of the bifurcations 11 are made rounding and are adapted to engage with the fixed jaw 2 and act thereon by a cam action to force the jaws apart when the lever is moved away from the shank at its free end as indicated most clearly in Fig. 2. 1t is to be understood that when the inner or free end of the lever 9 is thrown outward away from the shank 1, the bifurcations engaging with the fixed jaw 2 result in forcing the movable jaw f away from the fixed jaw, and compressing the spring 6. After the tool or other article to be gripped has been placed in position between the jaws 2 and f, the outer end of the lever 9 is moved towards the shank l, thereby permitting the spring 6 to act to draw the jaw 1 towards the jaw 2 and grip the tool. By having the bifurcations Ill. embrace opposite sides of the jaws, the latter are prevented from lateral displacement and are protected or housed.

The walls of the socket formed by the recesses in the faces of the jaws 2 and f flare outwardly; hence when pulling upon the shank 1 to withdraw a tool after the same has been advanced into a bore or opening the tendency is for the tool to slip outward in the said socket. In accordance with this invention, the jaws are automatically drawn together; hence at all times grip the shank of the tool and prevent: the same becoming loose, and when the shoulder usually provided at the base of the tool shank, engages the contracted end of the socket, the tool is prevented from further outward movement and the jaws being automatically drawn together, the tool is held firm and prevented from becoming loose or slipping from the socket.

Having thus described the invention, what is claimed as new is:

1. [n a bit stock, the combination of. a fixed jaw, a mov able jaw, a spring mounted upon the fixed jaw, and a link connecting the spring and the movable jaw.

2. In a bit stock, the combination of a fixed jaw, a movable jaw, a spring mounted upon the fixed jaw, a link connecting the spring and the movable jaw, and a lever for compressing the spring to release the jaws 3. In a bit stock, the combination of a fixed jaw, a movable jaw, a spring mounted upon the fixed jaw, a link e0nnecting the spring and the movable jaw, and a lever carried by the movable jaw and engaging the fixed jaw for compressing the spring to release the jaws.

4. In a bit tock, the combination of a fixed jaw, 21 movable jaw, a spring mounted upon the fixed jaw and serving to draw the movable jaw toward the same, and a lever carried by the movable jaw and having a cam engagement with the fixed jaw for releasing the said jaws.

5. A bit stock comprising a shank having a fixed jaw zit one end, said jaw being located to one side of a prolongation of the axis of the shank, and a complemental movable jaw arranged upon the opposite side of the prolongation of said axis, and a ilat spring placed along side of the shank and fixed jaw and secured at one end to the shank, and a link connecting the free end of the spring with-the movable jaw.

(3. A bit stock comprising a shank having a fixed jaw at one end, said jaw being located to one side of a prolong-a tion of the axis of the shank, and a complemental movable jaw arranged upon the opposite side of the prolongation of said axis, and a fiat spring placed along side of the shank and fixed jaw and secured at one end to the shank, and a link connecting the free end of the spring with the movable jaw, and an operating lever tulcrumed to one of the jaws and adapted to engage the other jaw to force the two jaws apart to admit of placing an article between them or removing a tool or the like when required.

7. In a bit stock, the combination of a shank provided with a fixed jaw, a coniplemental movable jaw, a spring placed along side of the shank and fixed jaw and secured at one end to the shank, an operating lever having a bifurcatod end embracing opposite sides of the movable jaw and 1 )ivoted thereto and adapted to engage the fixed jaw and a link Connecting the operating lever with the free end of the spring. I

R. In a bit stock, the combination of a. shank provided with a lixed jaw, acomplemental movable jaw, a spring placed alongside oi the shank and iixed jaw and secured at one end to the shank, an operating lever having a bitur (rated end embracing opposite sides of the movable jaw and pivoted thereto and adapted to engage the fixed jaw and comprising a hollow handle portion which is adapted to inclose the shank, spring and jaws when moved to a position against the said shank, and a link embracing the bifurcated end of the operating lever and connecting the same with the free end 01' the aforementioned spring.

ln testimony whereof I atiix my signature in presence of two Witnesses.

JOSEPH O. MICI-IAUD. [:L. s.]

Witnesses HENRY W. Nxnnxn, IIIl-INEE Cxn. 

